2 files changed, 61 insertions, 7 deletions

diff --git a/engine/src/lib.rs b/engine/src/lib.rs
index dc76b37..9d836c0 100644
--- a/engine/src/lib.rs
+++ b/engine/src/lib.rs
@@ -1,8 +1,10 @@
 #![deny(clippy::all, clippy::pedantic)]
 
+use std::collections::BTreeMap;
+
 use glfw::{Window, WindowBuilder};
 
-use crate::object::Object;
+use crate::object::{Id as ObjectId, Object};
 use crate::vector::Vec2;
 
 mod opengl;
@@ -19,6 +21,7 @@ pub use glfw::WindowSize;
 pub struct Engine
 {
     window: Window,
+    objects: BTreeMap<ObjectId, Object>,
 }
 
 impl Engine
@@ -49,19 +52,45 @@ impl Engine
 
         crate::renderer::initialize(&window).map_err(Error::InitializeRendererFailed)?;
 
-        Ok(Self { window })
+        Ok(Self {
+            window,
+            objects: BTreeMap::new(),
+        })
+    }
+
+    pub fn add_object(&mut self, object: Object)
+    {
+        self.objects.insert(object.id(), object);
+    }
+
+    pub fn set_objecs(&mut self, objects: impl IntoIterator<Item = Object>)
+    {
+        self.objects
+            .extend(objects.into_iter().map(|object| (object.id(), object)));
+    }
+
+    #[must_use]
+    pub fn get_object_by_id(&self, id: ObjectId) -> Option<&Object>
+    {
+        self.objects.get(&id)
+    }
+
+    #[must_use]
+    pub fn get_object_by_id_mut(&mut self, id: ObjectId) -> Option<&mut Object>
+    {
+        self.objects.get_mut(&id)
     }
 
     /// Starts the engine.
     ///
     /// # Errors
     /// Will return `Err` if updating the window fails.
-    pub fn start(&self, objects: &[Object], mut func: impl FnMut()) -> Result<(), Error>
+    pub fn start(&mut self, mut func: impl FnMut(&mut Self)) -> Result<(), Error>
     {
         while !self.window.should_close() {
-            func();
+            func(self);
 
-            crate::renderer::render(objects.iter().map(Object::renderable));
+            crate::renderer::render(self.objects.values().map(Object::renderable));
 
             self.window
                 .swap_buffers()
diff --git a/engine/src/object.rs b/engine/src/object.rs
index a650abc..11ba7e6 100644
--- a/engine/src/object.rs
+++ b/engine/src/object.rs
@@ -10,6 +10,7 @@ use crate::vertex::Vertex;
 #[derive(Debug)]
 pub struct Object
 {
+    id: Id,
     renderable: Renderable,
 }
 
@@ -19,7 +20,7 @@ impl Object
     ///
     /// # Errors
     /// Will return `Err` if shader creation fails or if shader program linking fails.
-    pub fn new(vertices: &[Vertex]) -> Result<Self, Error>
+    pub fn new(id: Id, vertices: &[Vertex]) -> Result<Self, Error>
     {
         let vertex_shader = Shader::new(ShaderKind::Vertex);
 
@@ -52,7 +53,14 @@ impl Object
 
         let renderable = Renderable::new(shader_program, vertices);
 
-        Ok(Self { renderable })
+        Ok(Self { id, renderable })
+    }
+
+    /// Returns the object ID.
+    #[must_use]
+    pub fn id(&self) -> Id
+    {
+        self.id
     }
 
     pub(crate) fn renderable(&self) -> &Renderable
@@ -74,3 +82,20 @@ pub enum Error
     #[error("Failed to link shader program")]
     LinkShaderProgramFailed(#[source] ShaderError),
 }
+
+/// Object ID.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct Id
+{
+    id: u16,
+}
+
+impl Id
+{
+    /// Returns a new object ID.
+    #[must_use]
+    pub fn new(id: u16) -> Self
+    {
+        Self { id }
+    }
+}